How old are Sophia Grace Brownlee and Rosie McClelland?

Sophia Grace Brownlee is 14 years old (born April 18, 2003).
Rosie McClelland is 10 years old (born September 7, 2006).

Sophia Grace was 8 and Rosie was 5 when the cousins made the video "Big Bass" (2011).
Sophia Grace was 11 and Rosie was 7 at the release of "Sophia Grace & Rosie's Royal Adventure" (May 2014).